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Summarize size of all files of given type in all subdirectories (in bytes)

This example summarize size of all pdf files in /tmp directory and its subdirectories (in bytes).

Replace "/tmp" with directory path of your choice and "\*pdf" or even "-iname \*pdf" with your own pattern to match specific type of files. You can replace also parameter for du to count kilo or megabytes, but because of du rounding the sum will not be correct (especially with lot of small files and megabytes counting).

In some cases you could probably use sth like this:

du -cb `find /tmp -type f -iname \*pdf`|tail -n 1

But be aware that this second command CANNOT count files with spaces in their names and it will cheat you, if there are some files matching the pattern that you don't have rights to read. The first oneliner is resistant to such problems (it will not count sizes of files which you cant read but will give you correct sum of rest of them).

which null-terminates the filenames, making the spaces not to be a problem. xargs is frequently used in concert with find, and in some cases your command will probably complete much sooner because instead of invoking du (as in this example) once on each file, xargs will invoke du on many arguments at once; still the same number of system calls, but fewer process creations. xargs can put the piped-in arguments at any location in a command using the -I (capital i) option.

Well, I want it to be more universal. Without "-type f" and counting for "\*java" pattern on some source tree will get me in troubles. I have here also some dirs called "java". The same with "\*mp3" on a whole system.

2)

You perfectly right. I was looking into some "-print" use but haven't got to "-print0". And I do not know "xargs" enough - I have to change it ;-). So the command could look like this: